What is Limb-Mammary Syndrome? Limb-mammary syndrome (LMS) is a rare autosomal dominant genetic disorder belonging to the group of ectodermal dysplasias. It is caused by mutations in the TP63 gene and features severe limb anomalies, such as deficiencies, duplications, or fusion/separation defects in the hands and feet (ectrodactyly), along with hypoplasia or aplasia of the mammary glands and...